Method of signaling.



R. A. FESSENDEN.

METHOD OF SIGNALING.

APPLIOATION 311,51) AUG. 21, 1005.

1,050,728, Patented Jan.14,1913.

3 SHEETSSHEET l.

R. A. FESSBNDEN. METHOD OF SIGNALING.

APPLICATION FILED AUG.2I,1S05. 1,05(),728 Patented Ja11.14,1913.-

3 SHBIITS SHBIJT 2.

FIE-1:7-

R. A. FESSBNDEN.

METHOD OF SIGNALING. APPLICATION FILED AUG. 21 1905. 1,050,728. Patented Jan. 14,1913.

3 SHEETS-$113131 3.

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Q WITNESSES: INVENTOR UNITED STATES PATENT-- orrion REGINALD A. rnssnmmn, or wasnme'ron, DISTRICT or conumnrafassmnon, BY

MESNE ASSIGNMENTS; TO SAMUEL M. KINTNER, OI- PITTSBURGH, PENNSYLVANIA,' AND HALSEY M. BARRETT, O-F BLOOMFIELD, NEW JERSEY, RECEIVERS.

METHOD OF SIGNALING;

1905. Serial Specification of Letters Patent; P atented J an. 14, 1913. I Original application filed July 27, 1905,'Scria1 No. 271,539. Divided and this application Ifiled August- 21, no. 275,165. i

To all whom it mayeoncem: 4 5

Be it known that I, REGINALD A. FESSEN- DEN, a citizen of the United States, and" resident of Washington, District of Columbia, have inventedja certain new and useful Method of Signaling, of which the following is a specification.

The invention described herein relates to certain methods of signaling generallyfbut more particularly to signaling by electromagnetic waves.

The primary object of my invention is to eliminate interference and inorease"the intensity of signals, by operating the indicator atthe receiving station b the conjoint energy of the received eectric imulses. and certain coo era-t' currents produced locally at the receiving station. This application furthermore contemplates the production of signals by means .of harmonic beats produced between the currents bf" the received electric pulses and the locally produced cooperating electric pulses,

the indicator being moved by the energy of the combined currents and therefore being under control, as to the frequency of I inotion, by the receiving operator.

The invention is hereinafter more fully described and claimed.

In the accompanying drawings, forminga partflof this specification, Figure 1 is a diagrammatic view illustrating a sending station; Fig. 2 illustrates a preferred mannor of drivlng and'controlling a high frequency generator-: 'Fig. 3 is a diagraminatic view of a combined sending and receiving station; Fig. 4 is a view similar to 3, illustrating modifications, and Fig. 5' illustrates my improvements applied toline wires. I

Agreaiesource of trouble in telegraphin isthe liability of signals being interfere with bytgdisturbances either atmospheric or 1 these meaning from a station or, stations- .a number ofmessages, si 0.

'tained lw'itl out making use ur e-sens other than that from which it is fiesirect'ta receive signals. These and other difiicule.

tiesxare overcome'by the methods fiiesc'ribed 2 herein, great sensitiveness is obtained,

als. -or .gi 'n tiolisecan' besent and received-at e time further, these results falthou h resonance effects inay be-"used if desire and are purposes. In the practice of my inventiomlIprefer to use for sending a means for producing continuous radiation, which may be for ex- 7 ample the high frequency generator having thecharacteristics described'in Patent No. 706,737 or the means described in Patent -No. 706,742. It is also preferred to use low voltage, as by the use of comparatively low voltage, which is especially adapted for use-with this improvement, 'and a practioall'y cont nuous emission of waves, except as effected by the signal producing means.

(as the key) the effects of sunlight are largely overcome, interference with neighboring stations is reduced and received.sig-- nals are selected more sharply. It is also. preferred to employ an aerial having a large capacity as described in U. S. Reissue Pat-- ents 12,168; 12,169; and horizontally arranged as in U. S. Patents 7 06,7 38 ;v 706,739

preferably used for some i 55 the received oscillations will flow may be arranged in operative relation to the re- %ceiving antennae. A frequency determining element controlling a locally produced field adapted to produce an interaction with the electrostatic orelectromagnetic field prowinced by received oscillations, is used at the receiving station. 1 -80.

. As a freqneney-controllmg;device,..it..-is., preferred to use a high frequencl -alter *nator, or othersuitable device- 'or pro} ducing 'uxiintermittent oscillations, as for; example, a'deviceoperati'n --by direct cur- 9 5 rent with or without dighrge ga as de scribed'in. Letters'Pate t No. 706,42 or a selector device as describedin U. 'S..1 atent I 793,652, where a high frequency alternator J is used, which latter case the field is steamer-gas) tui' he on-by; an. electric .motorg 5lfsuppli'ed froriiijst'orege' batteries:.52

the frequency is preferably maintained constant to about one-tenth (1 /10) of one per cent. (1%), by attaching a \Veston tachometer 54 to the shaft of the motor and placing an adjustable contact on the indicating pointer of the tachometer, so that when the speed-rises or falls, a suitable mechanism such as rheostat 53 will change the resistance in the field or armature of the motor, and thereby restore the speed to its proper value, as shown in Fig. Other means of regulation may be used, but that described is preferred, as the adjustable contact of the \Veston tachometer is capable of being adjusted to any desired point, and, when so adjusted, the speed is automatically maintained constant at that value.

In order to determine whether'or not the frequency has the proper value irrespective of mechanical means, a local independent. resonant circuit (comprising a condenser, preferably a compressed air condenser, and in inductance and a sending or receiving device) may be kept on the station for the purpose of forming a standard of frequency.

While a variety of forms of receiving devices may be employed, the construction shown in Fig. 3 is convenient and desirable. This form consists of a light coil of wire, 8, attached to a telephone diaphragm, 9, and a second coil, 10, arranged in operative relation to the coil 8, which is arranged in operative relation to the receiving antennae. Impulses generated and determinedliy the frequency determining element, for example,

I the current from the high frequency dyname, 5, or a transformer 11, connected therewith, flow through the coil, 10. In the circuit of the coil 10, an inductance 12, and capacity 13, both preferably variable, mayibe placed, and the phase of the current from the dynamo may be made to have any desired value.

In Fig. 1 is shown a form of sending apparatus consisting of an antenna, 1, having a-horizontal portion, 2, an inductance 3, and

a ap y, 4: (both preferably adjustable) for tunin purposes where this is desired. A hlgh 'requency alternator, 5, is operatively connected to the antenna 1, prefer-- ably through the transformer, 16. A key 7, or other suitable means, is employed for regulating or controlling the emissions of radiations from the antenna either by direct make or break as shown or by changing the intensity or frequency of the emitted radiation. The method of using the key to effeet a change in the character or amount of the radiation while keeping the load on the generator constant, shown in 3 by in u the contact 36, capacity 48, and etive resistance 37 is preferred. On the recei t of oscillations, current will flow through t e coil 8, and the oscillating field so produced will interact with the field produced by the coil 10. If the field from the coil 10, which is continuously active, is of a frequency exactly-the same as of the field from coil 8, produced by the received oscillations, no indication, or only a weak one, may be produced, as the phase of the currentmay not be suitable, the force exerted during one part of the cycle being counterbalanced by force in the opposite direction during the other part of the cycle, as is well known. It is preferred, therefore, to have the frequency of the dynamo producing a field from coil 10, dilferent from the frequency of the received oscillations, and this ditferencemay amountpreferably to about one-fifth (1/5) of one per cent. (1%), though a larger or a smaller difference may be used. If the frequency of the transmitted waves be 100,000 per second, and the frequenc of the alternator 8, be one-fifth (1/5) 0 one per cent. (1%) different from this; i. e. 100,200 beats will be produced, which will cause tht telephone diaphragm to vibrate and emit a musical note. If the frequency difference be too great, either beats will not be produced at all, or their pitch will be too high to be andible; while if the frequency difference be too small, the pitch of the beats will be too low to produce a musical note or even to produce an audible indication. The pitch of the note may be altered at will so as to produce mechanical resonance with the telephone diaphragm, or with a'resonator of any desired type, by changing the speed of the alternator 5. When in calling up the station beat tuning is used as it may be though it is not preferred, then after the station is called up the desired beat frequency can be obtained by adjusting the position of the fixed contact or the Weston tachometer relay or other speed regulating or frequency determining device.

If it is desired to send while receiving, the key 7 is depressed so as to make a signal, and the alternator 5 generates electromagnetic waves in the antenna by means of the transformer 16, whose secondary is operatively connected to the aerial 1. In this case the transmitted oscillations will produce no indication on the telephone diaphragm 9, because the frequency of the sending oscillations which oscillate in the antenna 1, and coil 8, will be the same as those in the coil 10, and hence no beats will e produced. The interaction between the coils 8 and 10, due to the'sending, can be made smaller by changing the phase in the coil 10, by means of the-adjustable inductance 12, or adjustable capacity 13, so as to make the phase of the currents in coil 10 and 8 different by 90.

.Another form of receiver is shown in Fig. 4 consisting of a ring, 14, referably oval or oblong, movably suspended or supported in such relation to the coils 8 and 10, as to be i within the influence of the fields produced by said coils. The ring. or circuit 14; is ad'- j usted to such an angle that the current produced by received oscillations in coil 8, will generate currents in the ring. The coil 10 which, as stated, isv connected tothe alternator through the variable inductance 12 and variable condenser 13, roduces a magnetic field which interactingv on the currents in t e ring 14, causes the latter to move. The motion of the rin lized to produce an indication 1n any of the many ways known inthe art. The .electrical constants of the ring, e. g. its resistance or self-inductance may be empirically arranged so as to prod feet; and with a similar end in view, the phases of the current in the coil 10 may be altered so as'to give a maximum effect in v the ring by means of the capacity 13, 0

the inductance12.

It will'be. understood that, althou h it is preferred to use-the same generator or producing a field by the coil 10, and also for v.sending, independent generators may be used for these purposes, as shown in Fig. 4. As shown in Fig. 3 two or moresignals, indications or messages may be sent at the same time by the employment of two or more dynamos, as 5 and 15, the alternator 15 having a frequency different from that of the alternator 5, and being operatively connected to the antenna 1, preferably through a transformer 16. A key 17,

or other suitable means, is employed for controlling the emissions produced by the alternator 15. p

In 'Fig 4, two or more si als, indications or messages may be receive simultaneously, in which case a second receiver, consisting of a coil, 18, secured to a diaphragm 19,'is operatively connected to the aerial, and a fixed coil, 20, is in circuit with an alter! nator, 21, a variable inductance and a variable capacity being also preferably included m-the circuit. The frequency of the. alter nator 21, should preferably be different from that of the alternator 5.

5e 3 Where it is desired to-"send two 'ormore messages, .or receive. two "or more messages simultaneouslm' lt is preferable to -h'ave the 'alternatorsof such- 'periodicities' that no' beats or inaudible beats, will-be produced between the alternator-s used at the-same station. Where'debired -au or any of the circuits-may be .tuned in accordelectrica ance with methods well wn inthe art, the advantages and 'efl'f. ts? of such tuning being well kno'wni Instead Iof-usin'g the arrangement'of Fig. 3 for maintaining the load the generator constan in which the contact 36, condenser 48Ia1id. inductive resistance 37 are used, as.

previously described, I may. accomplish the can be utiuce-a maximum efsame purpose by opening the switch 40 above" the coil 37, in which, case the fixed contact of the key 7 is-attached to a spring 33 fixed on the support 34 and-carrying the insulating rod 28. It has a contact 29. Innormal position of the key the contacts 29 and- 30 are connected, completing the circuit which contains inductance 32 and condenser31, the resistance 35 and thegenerator 5. On depressing the key 7 the circuit includingjthe fixed cbntact on sprin 33, the primary '6 of the transformer, an the generator 5, is. closed and waves are sent out, and the contacts 29, 30 are separated by the downward movementpf the rod 28, thereby openin the circuit 32, 31, 35, '5, 29. The release 0 the key 7 again opens the circuit 33, 6, 5, 7, and closes the circuit last above described. In this way the'electric'al constants of the generator. circuit are maintained the same whether the key is depressed or not.

w The ring 1 1, may be used to close and open a circuit, and thereby operate a bell or got-her indicating instrument of a relay, as shown in Fig. 4, the ring being suspended by a fine hosphor bronze wire, 22,'and provided with a contact point 23, adapted to be moved into contact with a point, 24, by the movement of the ring, and so close a circuit containing a battery 25, and bell or other 'indicating instrument, 26. A relay 27, may be included in this circuit and employed to 0perate any desired mechanism for sending out the received signal from the same or a dif- .ferent antenna for the purpose of relaying the signal or message. In the arrangement shown in Fig. 4,-the relay operates a key 38, to cause the igh frequency generator, 39, to

ing key, or other 'signalcontrolling mecha msm, whether operated by hand, by a relay,

or otherwise, in lieu of making and break- I ing a circuit, maybe used to alter the intensity or change the frequency. I v

' The advantages of this system are numer-' one, as it'is applicable not only to signaling 'by electromagnetic waves, but also to the transmission of signals by induction by line Wires and by' other means. Its advantages in regard. to all these methods are very great, and it is especially valuable for transmitting by. electroma etic. waves. jThlS method is practically Independent of resonance (though resonance circuits may be [used if desired) and hence the selectively can be, and is necessarily very sharp, being independent of resonance. A station less than one hundred feet awa cannot inter: fere with the receipt of slgnals, or even weaken them if its frequency difl'ersmore -send out signals from the antenna, 1. The v thana 'fraction'of one per cent. (1%) from.

"that of theimpulses, which it is desired to" 13.

receive. '-The ability to send and receive at the same time and to work multiplex is also a great value; as is also the case of operation in sending and receiving simultaneously by this method, as the sending does not interfere at all with the receipt of messages. Another advantage of using the beats method, instead of having the frequency at the receivii-ig end the same as that of the sending end, is that if the frequency at the receiving end were the same as that at the sending end, which, however, is commercially impracticable, the fixed coil would generate by induction currents in the movable coil, many thousand times greater than the currents which it is desired to receive, and hence the efiect of the impulses which it is desired to receive would be swamped by the1 currents generated by the local fixed CO1.

The use of a constantly active frequency determining-element is very import-ant, as it enables the locally generated impulses to be maintained at a constant intensity, and not to die off as trains of waves do. Where the intensity dies off, the effects produced would vary greatly, and to such an extent that it would not be possible to operate practically and commercially. 4 In. the method described herein a greatly intensified effect is obtained and also great certainty of operation by maintainlng the frequency determining element at the receiving station in a constantly active condition, and also by using at the sending station apparatus producing a practically continuous emission of radiation of a frequency slightly different from that of the frequency determining element at the receiving station.

As by the invention described herein signals may be simultaneously sent and received with absolutely no mutual disturbance, the invention is especially adapted for relaying. In connection with line wires and in the arrangement of Fig. 5 the frequency of the oscillation is made considerably lower and signals may be produced by shifting the phase of the transmitted impulses by shunting an inductance or capacity across the key, so that when the key is closed, the inductance or capacity of the whole circuit is altered. The sending or receiving aerials or both may be dead beat or non-resonant to any particularperiodicity. Two or more aerials may be used at the station, one for sending, one for receiving, and one for relaying, but aerials are not necessary, as the magnetic component methods described in Patent No. 1,020,032 granted March 12, 1912, may be used. Where desirable the aerials may be tuned to a given frequency and where two or more antennae are used they may have a common portion and the different sending or receiving devices may be placed in the branches as is well known in the art. This may also be done in the case where the sending or receiving conductors are not resonant but are practically dead beat.

The apparatus herein described, is claimed in my application No. 271,539 of which application this'is a division, an so is not claimed here, but

What I do claim as my invention and desire to secure by Letters Patent, is,

1. In the art of electric si aling, the method which consists in movlng an indicator at the receiving station by the interaction of the received impulses forming the signal, and a series of sustained electric impulses locally produced at the receiving station and maintained with a frequency near to but not the same as the frequency of the received impulses.

2. In the art of signaling, the method which consists in making an indication by the interaction of received impulses of sustained frequency and amplitude with impulses of neighboring frequency generated by a constantly acting local source of energy at the receiving station.

3. In the art of signaling, the method which consists in sending sustained oscillations and producing a signal at the receiving station by interaction of a field of force produced thereby, with a field of force produced by impulses continuously generated by a local source at the receiving station, having a frequency so differing from that of the received impulses as to produce beats.

4. In the art of signaling with high frequency currents, the method which consists in sending sustained oscillations, maintaining at the receiving station a constantly acting field of force, producing a cooperating field of force by the received impulses interacting with the locally produced field, and controllin such interaction by a constantly operating frequency determining element.

5. In the .art of signaling with high frequency currents, the method which consists in producing at the receiving station a constantly active field offorce excited by received oscillations, and a constantly active field of force excited by locally produced oscillations, causing the said two fields to interact and controlling such interaction to produce signals, by a constantly operating frequency determining element.

6. The method of signaling which consists in sendingsustained oscillations, and producing by them at the receiving station a field of force, maintaining a second field of force by sustained oscillations locally produced, causing the two fields of force to interact, and controlling such interaction by a frequency determining element so as to form beats bythe interaction.

7. The method of signaling which consists in sending sustained oscillations of one fre quency and producing at the receiving station a coacting field of force excited thereby, and maintaining a-second field of force excited by locally produced constantly sus-' tained oscillations of neighboring frequency to those received, whereby beats are produced, substantially as described.

8. The method of signaling which consists in receiving constantly sustained oscillations and producing a field thereby, causing interaction of said field [with a field excited by locally produced constantly sustained oscil-.

lations, and causin beats only when the 10- cally produced osclllations slightly differ in.

frequency from those received.

9. In the art of signaling, the method which comprises maintaining continuous high frequency oscillations for absorption by a receiving antenna, providing a local circuit to absorbenerg'y at the same rate, and supplying energy locally, and connecting said local source alternately to the local absorption circuit and to the antenna in Working the operating key, whereby to maintain the load on the source constant irrespective of the position of the key.

10. The method of transmitting and receiving sustained alternating signal impulses, which consists in transmit-ting a contln'uous wave train of sustained oscillations,

producing signals ,by changes in the fre-- queney of such wave train too small to be effectively observed by electrical resonance, and observing the minute variations in frequency of such transmitted wave train.

11. The method of transmitting and receiving sustained alternating signal impulses, which eonsists in transmitting a cont-inuous wave train of sustained oscillations, changing the frequency of such continuous wave train to produce signals, combining with such transmitted wave train at the receiver locally generated sustained oscillacelvmg tions and serving the combined effects of such Oscillu. ions.

12. The method of transmitting and recei'ving sustained alternating signal impulses, which consists in t'a-nsmitting a continuous wave train of sustained oscillations, changing the frequency of such continuous wave train to produce signals, combining with uch tr:msnntted wave tram at the receiver locally generated sustained oscillaturns of a different frequency and observing the beats produced by the combination of the effects of such oscillations.

13. The method of transmitting and resustained alternating signal impulses, which consists in transmitting a continuous ware train of sustained oscillations, combining with'such transmitted wave train at the receiver locally generated sustained oscillations of different frequency producing by combination with the transmitted wave train a definite beat rate, changing the frerates resulting from the different frequencies.

Signed at Brant Rock, Plymouth county, Mass, this 19th day of August, A. D. 1905.

REGINALD A. FESSEN DEN. Witnesses:

J. F. BEKCKLEY, J. E. BENT. 

